text: /*
   * Driver for the PLX NET2280 USB device controller.
   * Specs and errata are available from <http://www.plxtech.com>.
   *
   * PLX Technology Inc. (formerly NetChip Technology) supported the
   * development of this driver.
   *
   *
   * CODE STATUS HIGHLIGHTS
   *
   * This driver should work well with most "gadget" drivers, including
   * the File Storage, Serial, and Ethernet/RNDIS gadget drivers
   * as well as Gadget Zero and Gadgetfs.
   *
   * DMA is enabled by default.  Drivers using transfer queues might use
   * DMA chaining to remove IRQ latencies between transfers.  (Except when
   * short OUT transfers happen.)  Drivers can use the req->no_interrupt
   * hint to completely eliminate some IRQs, if a later IRQ is guaranteed
   * and DMA chaining is enabled.
   *
   * Note that almost all the errata workarounds here are only needed for
   * rev1 chips.  Rev1a silicon (0110) fixes almost all of them.
   */
  
  /*
   * Copyright (C) 2003 David Brownell
   * Copyright (C) 2003-2005 PLX Technology, Inc.
   *
   * Modified Seth Levy 2005 PLX Technology, Inc. to provide compatibility
   *	with 2282 chip
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   */
  
  #undef	DEBUG		/* messages on error and most fault paths */
  #undef	VERBOSE		/* extra debug messages (success too) */
  
  #include <linux/module.h>
  #include <linux/pci.h>
  #include <linux/dma-mapping.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/ioport.h>
  #include <linux/slab.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/timer.h>
  #include <linux/list.h>
  #include <linux/interrupt.h>
  #include <linux/moduleparam.h>
  #include <linux/device.h>
  #include <linux/usb/ch9.h>
  #include <linux/usb/gadget.h>
  #include <linux/prefetch.h>
  
  #include <asm/byteorder.h>
  #include <asm/io.h>
  #include <asm/irq.h>
  #include <asm/system.h>
  #include <asm/unaligned.h>
  
  
  #define	DRIVER_DESC		"PLX NET228x USB Peripheral Controller"
  #define	DRIVER_VERSION		"2005 Sept 27"
  
  #define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
  #define	EP_DONTUSE		13	/* nonzero */
  
  #define USE_RDK_LEDS		/* GPIO pins control three LEDs */
  
  
  static const char driver_name [] = "net2280";
  static const char driver_desc [] = DRIVER_DESC;
  
  static const char ep0name [] = "ep0";
  static const char *const ep_name [] = {
  	ep0name,
  	"ep-a", "ep-b", "ep-c", "ep-d",
  	"ep-e", "ep-f",
  };
  
  /* use_dma -- general goodness, fewer interrupts, less cpu load (vs PIO)
   * use_dma_chaining -- dma descriptor queueing gives even more irq reduction
   *
   * The net2280 DMA engines are not tightly integrated with their FIFOs;
   * not all cases are (yet) handled well in this driver or the silicon.
   * Some gadget drivers work better with the dma support here than others.
   * These two parameters let you use PIO or more aggressive DMA.
   */
  static bool use_dma = 1;
  static bool use_dma_chaining = 0;
  
  /* "modprobe net2280 use_dma=n" etc */
  module_param (use_dma, bool, S_IRUGO);
  module_param (use_dma_chaining, bool, S_IRUGO);
  
  
  /* mode 0 == ep-{a,b,c,d} 1K fifo each
   * mode 1 == ep-{a,b} 2K fifo each, ep-{c,d} unavailable
   * mode 2 == ep-a 2K fifo, ep-{b,c} 1K each, ep-d unavailable
   */
  static ushort fifo_mode = 0;
  
  /* "modprobe net2280 fifo_mode=1" etc */
  module_param (fifo_mode, ushort, 0644);
  
  /* enable_suspend -- When enabled, the driver will respond to
   * USB suspend requests by powering down the NET2280.  Otherwise,
   * USB suspend requests will be ignored.  This is acceptable for
   * self-powered devices
   */
  static bool enable_suspend = 0;
  
  /* "modprobe net2280 enable_suspend=1" etc */
  module_param (enable_suspend, bool, S_IRUGO);
  
  
  #define	DIR_STRING(bAddress) (((bAddress) & USB_DIR_IN) ? "in" : "out")
  
  #if defined(CONFIG_USB_GADGET_DEBUG_FILES) || defined (DEBUG)
  static char *type_string (u8 bmAttributes)
  {
  	switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
  	case USB_ENDPOINT_XFER_BULK:	return "bulk";
  	case USB_ENDPOINT_XFER_ISOC:	return "iso";
  	case USB_ENDPOINT_XFER_INT:	return "intr";
  	};
  	return "control";
  }
  #endif
  
  #include "net2280.h"
  
  #define valid_bit	cpu_to_le32 (1 << VALID_BIT)
  #define dma_done_ie	cpu_to_le32 (1 << DMA_DONE_INTERRUPT_ENABLE)
  
  /*-------------------------------------------------------------------------*/
  
  static int
  net2280_enable (struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
  {
  	struct net2280		*dev;
  	struct net2280_ep	*ep;
  	u32			max, tmp;
  	unsigned long		flags;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || !desc || ep->desc || _ep->name == ep0name
  			|| desc->bDescriptorType != USB_DT_ENDPOINT)
  		return -EINVAL;
  	dev = ep->dev;
  	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
  		return -ESHUTDOWN;
  
  	/* erratum 0119 workaround ties up an endpoint number */
  	if ((desc->bEndpointAddress & 0x0f) == EP_DONTUSE)
  		return -EDOM;
  
  	/* sanity check ep-e/ep-f since their fifos are small */
  	max = usb_endpoint_maxp (desc) & 0x1fff;
  	if (ep->num > 4 && max > 64)
  		return -ERANGE;
  
  	spin_lock_irqsave (&dev->lock, flags);
  	_ep->maxpacket = max & 0x7ff;
  	ep->desc = desc;
  
  	/* ep_reset() has already been called */
  	ep->stopped = 0;
  	ep->wedged = 0;
  	ep->out_overflow = 0;
  
  	/* set speed-dependent max packet; may kick in high bandwidth */
  	set_idx_reg (dev->regs, REG_EP_MAXPKT (dev, ep->num), max);
  
  	/* FIFO lines can't go to different packets.  PIO is ok, so
  	 * use it instead of troublesome (non-bulk) multi-packet DMA.
  	 */
  	if (ep->dma && (max % 4) != 0 && use_dma_chaining) {
  		DEBUG (ep->dev, "%s, no dma for maxpacket %d\n",
  			ep->ep.name, ep->ep.maxpacket);
  		ep->dma = NULL;
  	}
  
  	/* set type, direction, address; reset fifo counters */
  	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
  	tmp = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
  	if (tmp == USB_ENDPOINT_XFER_INT) {
  		/* erratum 0105 workaround prevents hs NYET */
  		if (dev->chiprev == 0100
  				&& dev->gadget.speed == USB_SPEED_HIGH
  				&& !(desc->bEndpointAddress & USB_DIR_IN))
  			writel ((1 << CLEAR_NAK_OUT_PACKETS_MODE),
  				&ep->regs->ep_rsp);
  	} else if (tmp == USB_ENDPOINT_XFER_BULK) {
  		/* catch some particularly blatant driver bugs */
  		if ((dev->gadget.speed == USB_SPEED_HIGH
  					&& max != 512)
  				|| (dev->gadget.speed == USB_SPEED_FULL
  					&& max > 64)) {
  			spin_unlock_irqrestore (&dev->lock, flags);
  			return -ERANGE;
  		}
  	}
  	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC) ? 1 : 0;
  	tmp <<= ENDPOINT_TYPE;
  	tmp |= desc->bEndpointAddress;
  	tmp |= (4 << ENDPOINT_BYTE_COUNT);	/* default full fifo lines */
  	tmp |= 1 << ENDPOINT_ENABLE;
  	wmb ();
  
  	/* for OUT transfers, block the rx fifo until a read is posted */
  	ep->is_in = (tmp & USB_DIR_IN) != 0;
  	if (!ep->is_in)
  		writel ((1 << SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
  	else if (dev->pdev->device != 0x2280) {
  		/* Added for 2282, Don't use nak packets on an in endpoint,
  		 * this was ignored on 2280
  		 */
  		writel ((1 << CLEAR_NAK_OUT_PACKETS)
  			| (1 << CLEAR_NAK_OUT_PACKETS_MODE), &ep->regs->ep_rsp);
  	}
  
  	writel (tmp, &ep->regs->ep_cfg);
  
  	/* enable irqs */
  	if (!ep->dma) {				/* pio, per-packet */
  		tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
  		writel (tmp, &dev->regs->pciirqenb0);
  
  		tmp = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
  			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE);
  		if (dev->pdev->device == 0x2280)
  			tmp |= readl (&ep->regs->ep_irqenb);
  		writel (tmp, &ep->regs->ep_irqenb);
  	} else {				/* dma, per-request */
  		tmp = (1 << (8 + ep->num));	/* completion */
  		tmp |= readl (&dev->regs->pciirqenb1);
  		writel (tmp, &dev->regs->pciirqenb1);
  
  		/* for short OUT transfers, dma completions can't
  		 * advance the queue; do it pio-style, by hand.
  		 * NOTE erratum 0112 workaround #2
  		 */
  		if ((desc->bEndpointAddress & USB_DIR_IN) == 0) {
  			tmp = (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT_ENABLE);
  			writel (tmp, &ep->regs->ep_irqenb);
  
  			tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
  			writel (tmp, &dev->regs->pciirqenb0);
  		}
  	}
  
  	tmp = desc->bEndpointAddress;
  	DEBUG (dev, "enabled %s (ep%d%s-%s) %s max %04x\n",
  		_ep->name, tmp & 0x0f, DIR_STRING (tmp),
  		type_string (desc->bmAttributes),
  		ep->dma ? "dma" : "pio", max);
  
  	/* pci writes may still be posted */
  	spin_unlock_irqrestore (&dev->lock, flags);
  	return 0;
  }
  
  static int handshake (u32 __iomem *ptr, u32 mask, u32 done, int usec)
  {
  	u32	result;
  
  	do {
  		result = readl (ptr);
  		if (result == ~(u32)0)		/* "device unplugged" */
  			return -ENODEV;
  		result &= mask;
  		if (result == done)
  			return 0;
  		udelay (1);
  		usec--;
  	} while (usec > 0);
  	return -ETIMEDOUT;
  }
  
  static const struct usb_ep_ops net2280_ep_ops;
  
  static void ep_reset (struct net2280_regs __iomem *regs, struct net2280_ep *ep)
  {
  	u32		tmp;
  
  	ep->desc = NULL;
  	INIT_LIST_HEAD (&ep->queue);
  
  	ep->ep.maxpacket = ~0;
  	ep->ep.ops = &net2280_ep_ops;
  
  	/* disable the dma, irqs, endpoint... */
  	if (ep->dma) {
  		writel (0, &ep->dma->dmactl);
  		writel (  (1 << DMA_SCATTER_GATHER_DONE_INTERRUPT)
  			| (1 << DMA_TRANSACTION_DONE_INTERRUPT)
  			| (1 << DMA_ABORT)
  			, &ep->dma->dmastat);
  
  		tmp = readl (&regs->pciirqenb0);
  		tmp &= ~(1 << ep->num);
  		writel (tmp, &regs->pciirqenb0);
  	} else {
  		tmp = readl (&regs->pciirqenb1);
  		tmp &= ~(1 << (8 + ep->num));	/* completion */
  		writel (tmp, &regs->pciirqenb1);
  	}
  	writel (0, &ep->regs->ep_irqenb);
  
  	/* init to our chosen defaults, notably so that we NAK OUT
  	 * packets until the driver queues a read (+note erratum 0112)
  	 */
  	if (!ep->is_in || ep->dev->pdev->device == 0x2280) {
  		tmp = (1 << SET_NAK_OUT_PACKETS_MODE)
  		| (1 << SET_NAK_OUT_PACKETS)
  		| (1 << CLEAR_EP_HIDE_STATUS_PHASE)
  		| (1 << CLEAR_INTERRUPT_MODE);
  	} else {
  		/* added for 2282 */
  		tmp = (1 << CLEAR_NAK_OUT_PACKETS_MODE)
  		| (1 << CLEAR_NAK_OUT_PACKETS)
  		| (1 << CLEAR_EP_HIDE_STATUS_PHASE)
  		| (1 << CLEAR_INTERRUPT_MODE);
  	}
  
  	if (ep->num != 0) {
  		tmp |= (1 << CLEAR_ENDPOINT_TOGGLE)
  			| (1 << CLEAR_ENDPOINT_HALT);
  	}
  	writel (tmp, &ep->regs->ep_rsp);
  
  	/* scrub most status bits, and flush any fifo state */
  	if (ep->dev->pdev->device == 0x2280)
  		tmp = (1 << FIFO_OVERFLOW)
  			| (1 << FIFO_UNDERFLOW);
  	else
  		tmp = 0;
  
  	writel (tmp | (1 << TIMEOUT)
  		| (1 << USB_STALL_SENT)
  		| (1 << USB_IN_NAK_SENT)
  		| (1 << USB_IN_ACK_RCVD)
  		| (1 << USB_OUT_PING_NAK_SENT)
  		| (1 << USB_OUT_ACK_SENT)
  		| (1 << FIFO_FLUSH)
  		| (1 << SHORT_PACKET_OUT_DONE_INTERRUPT)
  		| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)
  		| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
  		| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
  		| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  		| (1 << DATA_IN_TOKEN_INTERRUPT)
  		, &ep->regs->ep_stat);
  
  	/* fifo size is handled separately */
  }
  
  static void nuke (struct net2280_ep *);
  
  static int net2280_disable (struct usb_ep *_ep)
  {
  	struct net2280_ep	*ep;
  	unsigned long		flags;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || !ep->desc || _ep->name == ep0name)
  		return -EINVAL;
  
  	spin_lock_irqsave (&ep->dev->lock, flags);
  	nuke (ep);
  	ep_reset (ep->dev->regs, ep);
  
  	VDEBUG (ep->dev, "disabled %s %s\n",
  			ep->dma ? "dma" : "pio", _ep->name);
  
  	/* synch memory views with the device */
  	(void) readl (&ep->regs->ep_cfg);
  
  	if (use_dma && !ep->dma && ep->num >= 1 && ep->num <= 4)
  		ep->dma = &ep->dev->dma [ep->num - 1];
  
  	spin_unlock_irqrestore (&ep->dev->lock, flags);
  	return 0;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static struct usb_request *
  net2280_alloc_request (struct usb_ep *_ep, gfp_t gfp_flags)
  {
  	struct net2280_ep	*ep;
  	struct net2280_request	*req;
  
  	if (!_ep)
  		return NULL;
  	ep = container_of (_ep, struct net2280_ep, ep);
  
  	req = kzalloc(sizeof(*req), gfp_flags);
  	if (!req)
  		return NULL;
  
  	req->req.dma = DMA_ADDR_INVALID;
  	INIT_LIST_HEAD (&req->queue);
  
  	/* this dma descriptor may be swapped with the previous dummy */
  	if (ep->dma) {
  		struct net2280_dma	*td;
  
  		td = pci_pool_alloc (ep->dev->requests, gfp_flags,
  				&req->td_dma);
  		if (!td) {
  			kfree (req);
  			return NULL;
  		}
  		td->dmacount = 0;	/* not VALID */
  		td->dmaaddr = cpu_to_le32 (DMA_ADDR_INVALID);
  		td->dmadesc = td->dmaaddr;
  		req->td = td;
  	}
  	return &req->req;
  }
  
  static void
  net2280_free_request (struct usb_ep *_ep, struct usb_request *_req)
  {
  	struct net2280_ep	*ep;
  	struct net2280_request	*req;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || !_req)
  		return;
  
  	req = container_of (_req, struct net2280_request, req);
  	WARN_ON (!list_empty (&req->queue));
  	if (req->td)
  		pci_pool_free (ep->dev->requests, req->td, req->td_dma);
  	kfree (req);
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* load a packet into the fifo we use for usb IN transfers.
   * works for all endpoints.
   *
   * NOTE: pio with ep-a..ep-d could stuff multiple packets into the fifo
   * at a time, but this code is simpler because it knows it only writes
   * one packet.  ep-a..ep-d should use dma instead.
   */
  static void
  write_fifo (struct net2280_ep *ep, struct usb_request *req)
  {
  	struct net2280_ep_regs	__iomem *regs = ep->regs;
  	u8			*buf;
  	u32			tmp;
  	unsigned		count, total;
  
  	/* INVARIANT:  fifo is currently empty. (testable) */
  
  	if (req) {
  		buf = req->buf + req->actual;
  		prefetch (buf);
  		total = req->length - req->actual;
  	} else {
  		total = 0;
  		buf = NULL;
  	}
  
  	/* write just one packet at a time */
  	count = ep->ep.maxpacket;
  	if (count > total)	/* min() cannot be used on a bitfield */
  		count = total;
  
  	VDEBUG (ep->dev, "write %s fifo (IN) %d bytes%s req %p\n",
  			ep->ep.name, count,
  			(count != ep->ep.maxpacket) ? " (short)" : "",
  			req);
  	while (count >= 4) {
  		/* NOTE be careful if you try to align these. fifo lines
  		 * should normally be full (4 bytes) and successive partial
  		 * lines are ok only in certain cases.
  		 */
  		tmp = get_unaligned ((u32 *)buf);
  		cpu_to_le32s (&tmp);
  		writel (tmp, &regs->ep_data);
  		buf += 4;
  		count -= 4;
  	}
  
  	/* last fifo entry is "short" unless we wrote a full packet.
  	 * also explicitly validate last word in (periodic) transfers
  	 * when maxpacket is not a multiple of 4 bytes.
  	 */
  	if (count || total < ep->ep.maxpacket) {
  		tmp = count ? get_unaligned ((u32 *)buf) : count;
  		cpu_to_le32s (&tmp);
  		set_fifo_bytecount (ep, count & 0x03);
  		writel (tmp, &regs->ep_data);
  	}
  
  	/* pci writes may still be posted */
  }
  
  /* work around erratum 0106: PCI and USB race over the OUT fifo.
   * caller guarantees chiprev 0100, out endpoint is NAKing, and
   * there's no real data in the fifo.
   *
   * NOTE:  also used in cases where that erratum doesn't apply:
   * where the host wrote "too much" data to us.
   */
  static void out_flush (struct net2280_ep *ep)
  {
  	u32	__iomem *statp;
  	u32	tmp;
  
  	ASSERT_OUT_NAKING (ep);
  
  	statp = &ep->regs->ep_stat;
  	writel (  (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  		| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
  		, statp);
  	writel ((1 << FIFO_FLUSH), statp);
  	mb ();
  	tmp = readl (statp);
  	if (tmp & (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  			/* high speed did bulk NYET; fifo isn't filling */
  			&& ep->dev->gadget.speed == USB_SPEED_FULL) {
  		unsigned	usec;
  
  		usec = 50;		/* 64 byte bulk/interrupt */
  		handshake (statp, (1 << USB_OUT_PING_NAK_SENT),
  				(1 << USB_OUT_PING_NAK_SENT), usec);
  		/* NAK done; now CLEAR_NAK_OUT_PACKETS is safe */
  	}
  }
  
  /* unload packet(s) from the fifo we use for usb OUT transfers.
   * returns true iff the request completed, because of short packet
   * or the request buffer having filled with full packets.
   *
   * for ep-a..ep-d this will read multiple packets out when they
   * have been accepted.
   */
  static int
  read_fifo (struct net2280_ep *ep, struct net2280_request *req)
  {
  	struct net2280_ep_regs	__iomem *regs = ep->regs;
  	u8			*buf = req->req.buf + req->req.actual;
  	unsigned		count, tmp, is_short;
  	unsigned		cleanup = 0, prevent = 0;
  
  	/* erratum 0106 ... packets coming in during fifo reads might
  	 * be incompletely rejected.  not all cases have workarounds.
  	 */
  	if (ep->dev->chiprev == 0x0100
  			&& ep->dev->gadget.speed == USB_SPEED_FULL) {
  		udelay (1);
  		tmp = readl (&ep->regs->ep_stat);
  		if ((tmp & (1 << NAK_OUT_PACKETS)))
  			cleanup = 1;
  		else if ((tmp & (1 << FIFO_FULL))) {
  			start_out_naking (ep);
  			prevent = 1;
  		}
  		/* else: hope we don't see the problem */
  	}
  
  	/* never overflow the rx buffer. the fifo reads packets until
  	 * it sees a short one; we might not be ready for them all.
  	 */
  	prefetchw (buf);
  	count = readl (&regs->ep_avail);
  	if (unlikely (count == 0)) {
  		udelay (1);
  		tmp = readl (&ep->regs->ep_stat);
  		count = readl (&regs->ep_avail);
  		/* handled that data already? */
  		if (count == 0 && (tmp & (1 << NAK_OUT_PACKETS)) == 0)
  			return 0;
  	}
  
  	tmp = req->req.length - req->req.actual;
  	if (count > tmp) {
  		/* as with DMA, data overflow gets flushed */
  		if ((tmp % ep->ep.maxpacket) != 0) {
  			ERROR (ep->dev,
  				"%s out fifo %d bytes, expected %d\n",
  				ep->ep.name, count, tmp);
  			req->req.status = -EOVERFLOW;
  			cleanup = 1;
  			/* NAK_OUT_PACKETS will be set, so flushing is safe;
  			 * the next read will start with the next packet
  			 */
  		} /* else it's a ZLP, no worries */
  		count = tmp;
  	}
  	req->req.actual += count;
  
  	is_short = (count == 0) || ((count % ep->ep.maxpacket) != 0);
  
  	VDEBUG (ep->dev, "read %s fifo (OUT) %d bytes%s%s%s req %p %d/%d\n",
  			ep->ep.name, count, is_short ? " (short)" : "",
  			cleanup ? " flush" : "", prevent ? " nak" : "",
  			req, req->req.actual, req->req.length);
  
  	while (count >= 4) {
  		tmp = readl (&regs->ep_data);
  		cpu_to_le32s (&tmp);
  		put_unaligned (tmp, (u32 *)buf);
  		buf += 4;
  		count -= 4;
  	}
  	if (count) {
  		tmp = readl (&regs->ep_data);
  		/* LE conversion is implicit here: */
  		do {
  			*buf++ = (u8) tmp;
  			tmp >>= 8;
  		} while (--count);
  	}
  	if (cleanup)
  		out_flush (ep);
  	if (prevent) {
  		writel ((1 << CLEAR_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
  		(void) readl (&ep->regs->ep_rsp);
  	}
  
  	return is_short || ((req->req.actual == req->req.length)
  				&& !req->req.zero);
  }
  
  /* fill out dma descriptor to match a given request */
  static void
  fill_dma_desc (struct net2280_ep *ep, struct net2280_request *req, int valid)
  {
  	struct net2280_dma	*td = req->td;
  	u32			dmacount = req->req.length;
  
  	/* don't let DMA continue after a short OUT packet,
  	 * so overruns can't affect the next transfer.
  	 * in case of overruns on max-size packets, we can't
  	 * stop the fifo from filling but we can flush it.
  	 */
  	if (ep->is_in)
  		dmacount |= (1 << DMA_DIRECTION);
  	if ((!ep->is_in && (dmacount % ep->ep.maxpacket) != 0)
  			|| ep->dev->pdev->device != 0x2280)
  		dmacount |= (1 << END_OF_CHAIN);
  
  	req->valid = valid;
  	if (valid)
  		dmacount |= (1 << VALID_BIT);
  	if (likely(!req->req.no_interrupt || !use_dma_chaining))
  		dmacount |= (1 << DMA_DONE_INTERRUPT_ENABLE);
  
  	/* td->dmadesc = previously set by caller */
  	td->dmaaddr = cpu_to_le32 (req->req.dma);
  
  	/* 2280 may be polling VALID_BIT through ep->dma->dmadesc */
  	wmb ();
  	td->dmacount = cpu_to_le32(dmacount);
  }
  
  static const u32 dmactl_default =
  		  (1 << DMA_SCATTER_GATHER_DONE_INTERRUPT)
  		| (1 << DMA_CLEAR_COUNT_ENABLE)
  		/* erratum 0116 workaround part 1 (use POLLING) */
  		| (POLL_100_USEC << DESCRIPTOR_POLLING_RATE)
  		| (1 << DMA_VALID_BIT_POLLING_ENABLE)
  		| (1 << DMA_VALID_BIT_ENABLE)
  		| (1 << DMA_SCATTER_GATHER_ENABLE)
  		/* erratum 0116 workaround part 2 (no AUTOSTART) */
  		| (1 << DMA_ENABLE);
  
  static inline void spin_stop_dma (struct net2280_dma_regs __iomem *dma)
  {
  	handshake (&dma->dmactl, (1 << DMA_ENABLE), 0, 50);
  }
  
  static inline void stop_dma (struct net2280_dma_regs __iomem *dma)
  {
  	writel (readl (&dma->dmactl) & ~(1 << DMA_ENABLE), &dma->dmactl);
  	spin_stop_dma (dma);
  }
  
  static void start_queue (struct net2280_ep *ep, u32 dmactl, u32 td_dma)
  {
  	struct net2280_dma_regs	__iomem *dma = ep->dma;
  	unsigned int tmp = (1 << VALID_BIT) | (ep->is_in << DMA_DIRECTION);
  
  	if (ep->dev->pdev->device != 0x2280)
  		tmp |= (1 << END_OF_CHAIN);
  
  	writel (tmp, &dma->dmacount);
  	writel (readl (&dma->dmastat), &dma->dmastat);
  
  	writel (td_dma, &dma->dmadesc);
  	writel (dmactl, &dma->dmactl);
  
  	/* erratum 0116 workaround part 3:  pci arbiter away from net2280 */
  	(void) readl (&ep->dev->pci->pcimstctl);
  
  	writel ((1 << DMA_START), &dma->dmastat);
  
  	if (!ep->is_in)
  		stop_out_naking (ep);
  }
  
  static void start_dma (struct net2280_ep *ep, struct net2280_request *req)
  {
  	u32			tmp;
  	struct net2280_dma_regs	__iomem *dma = ep->dma;
  
  	/* FIXME can't use DMA for ZLPs */
  
  	/* on this path we "know" there's no dma active (yet) */
  	WARN_ON (readl (&dma->dmactl) & (1 << DMA_ENABLE));
  	writel (0, &ep->dma->dmactl);
  
  	/* previous OUT packet might have been short */
  	if (!ep->is_in && ((tmp = readl (&ep->regs->ep_stat))
  				& (1 << NAK_OUT_PACKETS)) != 0) {
  		writel ((1 << SHORT_PACKET_TRANSFERRED_INTERRUPT),
  			&ep->regs->ep_stat);
  
  		tmp = readl (&ep->regs->ep_avail);
  		if (tmp) {
  			writel (readl (&dma->dmastat), &dma->dmastat);
  
  			/* transfer all/some fifo data */
  			writel (req->req.dma, &dma->dmaaddr);
  			tmp = min (tmp, req->req.length);
  
  			/* dma irq, faking scatterlist status */
  			req->td->dmacount = cpu_to_le32 (req->req.length - tmp);
  			writel ((1 << DMA_DONE_INTERRUPT_ENABLE)
  				| tmp, &dma->dmacount);
  			req->td->dmadesc = 0;
  			req->valid = 1;
  
  			writel ((1 << DMA_ENABLE), &dma->dmactl);
  			writel ((1 << DMA_START), &dma->dmastat);
  			return;
  		}
  	}
  
  	tmp = dmactl_default;
  
  	/* force packet boundaries between dma requests, but prevent the
  	 * controller from automagically writing a last "short" packet
  	 * (zero length) unless the driver explicitly said to do that.
  	 */
  	if (ep->is_in) {
  		if (likely ((req->req.length % ep->ep.maxpacket) != 0
  				|| req->req.zero)) {
  			tmp |= (1 << DMA_FIFO_VALIDATE);
  			ep->in_fifo_validate = 1;
  		} else
  			ep->in_fifo_validate = 0;
  	}
  
  	/* init req->td, pointing to the current dummy */
  	req->td->dmadesc = cpu_to_le32 (ep->td_dma);
  	fill_dma_desc (ep, req, 1);
  
  	if (!use_dma_chaining)
  		req->td->dmacount |= cpu_to_le32 (1 << END_OF_CHAIN);
  
  	start_queue (ep, tmp, req->td_dma);
  }
  
  static inline void
  queue_dma (struct net2280_ep *ep, struct net2280_request *req, int valid)
  {
  	struct net2280_dma	*end;
  	dma_addr_t		tmp;
  
  	/* swap new dummy for old, link; fill and maybe activate */
  	end = ep->dummy;
  	ep->dummy = req->td;
  	req->td = end;
  
  	tmp = ep->td_dma;
  	ep->td_dma = req->td_dma;
  	req->td_dma = tmp;
  
  	end->dmadesc = cpu_to_le32 (ep->td_dma);
  
  	fill_dma_desc (ep, req, valid);
  }
  
  static void
  done (struct net2280_ep *ep, struct net2280_request *req, int status)
  {
  	struct net2280		*dev;
  	unsigned		stopped = ep->stopped;
  
  	list_del_init (&req->queue);
  
  	if (req->req.status == -EINPROGRESS)
  		req->req.status = status;
  	else
  		status = req->req.status;
  
  	dev = ep->dev;
  	if (req->mapped) {
  		pci_unmap_single (dev->pdev, req->req.dma, req->req.length,
  			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
  		req->req.dma = DMA_ADDR_INVALID;
  		req->mapped = 0;
  	}
  
  	if (status && status != -ESHUTDOWN)
  		VDEBUG (dev, "complete %s req %p stat %d len %u/%u\n",
  			ep->ep.name, &req->req, status,
  			req->req.actual, req->req.length);
  
  	/* don't modify queue heads during completion callback */
  	ep->stopped = 1;
  	spin_unlock (&dev->lock);
  	req->req.complete (&ep->ep, &req->req);
  	spin_lock (&dev->lock);
  	ep->stopped = stopped;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static int
  net2280_queue (struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
  {
  	struct net2280_request	*req;
  	struct net2280_ep	*ep;
  	struct net2280		*dev;
  	unsigned long		flags;
  
  	/* we always require a cpu-view buffer, so that we can
  	 * always use pio (as fallback or whatever).
  	 */
  	req = container_of (_req, struct net2280_request, req);
  	if (!_req || !_req->complete || !_req->buf
  			|| !list_empty (&req->queue))
  		return -EINVAL;
  	if (_req->length > (~0 & DMA_BYTE_COUNT_MASK))
  		return -EDOM;
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || (!ep->desc && ep->num != 0))
  		return -EINVAL;
  	dev = ep->dev;
  	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
  		return -ESHUTDOWN;
  
  	/* FIXME implement PIO fallback for ZLPs with DMA */
  	if (ep->dma && _req->length == 0)
  		return -EOPNOTSUPP;
  
  	/* set up dma mapping in case the caller didn't */
  	if (ep->dma && _req->dma == DMA_ADDR_INVALID) {
  		_req->dma = pci_map_single (dev->pdev, _req->buf, _req->length,
  			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
  		req->mapped = 1;
  	}
  
  #if 0
  	VDEBUG (dev, "%s queue req %p, len %d buf %p\n",
  			_ep->name, _req, _req->length, _req->buf);
  #endif
  
  	spin_lock_irqsave (&dev->lock, flags);
  
  	_req->status = -EINPROGRESS;
  	_req->actual = 0;
  
  	/* kickstart this i/o queue? */
  	if (list_empty (&ep->queue) && !ep->stopped) {
  		/* use DMA if the endpoint supports it, else pio */
  		if (ep->dma)
  			start_dma (ep, req);
  		else {
  			/* maybe there's no control data, just status ack */
  			if (ep->num == 0 && _req->length == 0) {
  				allow_status (ep);
  				done (ep, req, 0);
  				VDEBUG (dev, "%s status ack\n", ep->ep.name);
  				goto done;
  			}
  
  			/* PIO ... stuff the fifo, or unblock it.  */
  			if (ep->is_in)
  				write_fifo (ep, _req);
  			else if (list_empty (&ep->queue)) {
  				u32	s;
  
  				/* OUT FIFO might have packet(s) buffered */
  				s = readl (&ep->regs->ep_stat);
  				if ((s & (1 << FIFO_EMPTY)) == 0) {
  					/* note:  _req->short_not_ok is
  					 * ignored here since PIO _always_
  					 * stops queue advance here, and
  					 * _req->status doesn't change for
  					 * short reads (only _req->actual)
  					 */
  					if (read_fifo (ep, req)) {
  						done (ep, req, 0);
  						if (ep->num == 0)
  							allow_status (ep);
  						/* don't queue it */
  						req = NULL;
  					} else
  						s = readl (&ep->regs->ep_stat);
  				}
  
  				/* don't NAK, let the fifo fill */
  				if (req && (s & (1 << NAK_OUT_PACKETS)))
  					writel ((1 << CLEAR_NAK_OUT_PACKETS),
  							&ep->regs->ep_rsp);
  			}
  		}
  
  	} else if (ep->dma) {
  		int	valid = 1;
  
  		if (ep->is_in) {
  			int	expect;
  
  			/* preventing magic zlps is per-engine state, not
  			 * per-transfer; irq logic must recover hiccups.
  			 */
  			expect = likely (req->req.zero
  				|| (req->req.length % ep->ep.maxpacket) != 0);
  			if (expect != ep->in_fifo_validate)
  				valid = 0;
  		}
  		queue_dma (ep, req, valid);
  
  	} /* else the irq handler advances the queue. */
  
  	ep->responded = 1;
  	if (req)
  		list_add_tail (&req->queue, &ep->queue);
  done:
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	/* pci writes may still be posted */
  	return 0;
  }
  
  static inline void
  dma_done (
  	struct net2280_ep *ep,
  	struct net2280_request *req,
  	u32 dmacount,
  	int status
  )
  {
  	req->req.actual = req->req.length - (DMA_BYTE_COUNT_MASK & dmacount);
  	done (ep, req, status);
  }
  
  static void restart_dma (struct net2280_ep *ep);
  
  static void scan_dma_completions (struct net2280_ep *ep)
  {
  	/* only look at descriptors that were "naturally" retired,
  	 * so fifo and list head state won't matter
  	 */
  	while (!list_empty (&ep->queue)) {
  		struct net2280_request	*req;
  		u32			tmp;
  
  		req = list_entry (ep->queue.next,
  				struct net2280_request, queue);
  		if (!req->valid)
  			break;
  		rmb ();
  		tmp = le32_to_cpup (&req->td->dmacount);
  		if ((tmp & (1 << VALID_BIT)) != 0)
  			break;
  
  		/* SHORT_PACKET_TRANSFERRED_INTERRUPT handles "usb-short"
  		 * cases where DMA must be aborted; this code handles
  		 * all non-abort DMA completions.
  		 */
  		if (unlikely (req->td->dmadesc == 0)) {
  			/* paranoia */
  			tmp = readl (&ep->dma->dmacount);
  			if (tmp & DMA_BYTE_COUNT_MASK)
  				break;
  			/* single transfer mode */
  			dma_done (ep, req, tmp, 0);
  			break;
  		} else if (!ep->is_in
  				&& (req->req.length % ep->ep.maxpacket) != 0) {
  			tmp = readl (&ep->regs->ep_stat);
  
  			/* AVOID TROUBLE HERE by not issuing short reads from
  			 * your gadget driver.  That helps avoids errata 0121,
  			 * 0122, and 0124; not all cases trigger the warning.
  			 */
  			if ((tmp & (1 << NAK_OUT_PACKETS)) == 0) {
  				WARNING (ep->dev, "%s lost packet sync!\n",
  						ep->ep.name);
  				req->req.status = -EOVERFLOW;
  			} else if ((tmp = readl (&ep->regs->ep_avail)) != 0) {
  				/* fifo gets flushed later */
  				ep->out_overflow = 1;
  				DEBUG (ep->dev, "%s dma, discard %d len %d\n",
  						ep->ep.name, tmp,
  						req->req.length);
  				req->req.status = -EOVERFLOW;
  			}
  		}
  		dma_done (ep, req, tmp, 0);
  	}
  }
  
  static void restart_dma (struct net2280_ep *ep)
  {
  	struct net2280_request	*req;
  	u32			dmactl = dmactl_default;
  
  	if (ep->stopped)
  		return;
  	req = list_entry (ep->queue.next, struct net2280_request, queue);
  
  	if (!use_dma_chaining) {
  		start_dma (ep, req);
  		return;
  	}
  
  	/* the 2280 will be processing the queue unless queue hiccups after
  	 * the previous transfer:
  	 *  IN:   wanted automagic zlp, head doesn't (or vice versa)
  	 *        DMA_FIFO_VALIDATE doesn't init from dma descriptors.
  	 *  OUT:  was "usb-short", we must restart.
  	 */
  	if (ep->is_in && !req->valid) {
  		struct net2280_request	*entry, *prev = NULL;
  		int			reqmode, done = 0;
  
  		DEBUG (ep->dev, "%s dma hiccup td %p\n", ep->ep.name, req->td);
  		ep->in_fifo_validate = likely (req->req.zero
  			|| (req->req.length % ep->ep.maxpacket) != 0);
  		if (ep->in_fifo_validate)
  			dmactl |= (1 << DMA_FIFO_VALIDATE);
  		list_for_each_entry (entry, &ep->queue, queue) {
  			__le32		dmacount;
  
  			if (entry == req)
  				continue;
  			dmacount = entry->td->dmacount;
  			if (!done) {
  				reqmode = likely (entry->req.zero
  					|| (entry->req.length
  						% ep->ep.maxpacket) != 0);
  				if (reqmode == ep->in_fifo_validate) {
  					entry->valid = 1;
  					dmacount |= valid_bit;
  					entry->td->dmacount = dmacount;
  					prev = entry;
  					continue;
  				} else {
  					/* force a hiccup */
  					prev->td->dmacount |= dma_done_ie;
  					done = 1;
  				}
  			}
  
  			/* walk the rest of the queue so unlinks behave */
  			entry->valid = 0;
  			dmacount &= ~valid_bit;
  			entry->td->dmacount = dmacount;
  			prev = entry;
  		}
  	}
  
  	writel (0, &ep->dma->dmactl);
  	start_queue (ep, dmactl, req->td_dma);
  }
  
  static void abort_dma (struct net2280_ep *ep)
  {
  	/* abort the current transfer */
  	if (likely (!list_empty (&ep->queue))) {
  		/* FIXME work around errata 0121, 0122, 0124 */
  		writel ((1 << DMA_ABORT), &ep->dma->dmastat);
  		spin_stop_dma (ep->dma);
  	} else
  		stop_dma (ep->dma);
  	scan_dma_completions (ep);
  }
  
  /* dequeue ALL requests */
  static void nuke (struct net2280_ep *ep)
  {
  	struct net2280_request	*req;
  
  	/* called with spinlock held */
  	ep->stopped = 1;
  	if (ep->dma)
  		abort_dma (ep);
  	while (!list_empty (&ep->queue)) {
  		req = list_entry (ep->queue.next,
  				struct net2280_request,
  				queue);
  		done (ep, req, -ESHUTDOWN);
  	}
  }
  
  /* dequeue JUST ONE request */
  static int net2280_dequeue (struct usb_ep *_ep, struct usb_request *_req)
  {
  	struct net2280_ep	*ep;
  	struct net2280_request	*req;
  	unsigned long		flags;
  	u32			dmactl;
  	int			stopped;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || (!ep->desc && ep->num != 0) || !_req)
  		return -EINVAL;
  
  	spin_lock_irqsave (&ep->dev->lock, flags);
  	stopped = ep->stopped;
  
  	/* quiesce dma while we patch the queue */
  	dmactl = 0;
  	ep->stopped = 1;
  	if (ep->dma) {
  		dmactl = readl (&ep->dma->dmactl);
  		/* WARNING erratum 0127 may kick in ... */
  		stop_dma (ep->dma);
  		scan_dma_completions (ep);
  	}
  
  	/* make sure it's still queued on this endpoint */
  	list_for_each_entry (req, &ep->queue, queue) {
  		if (&req->req == _req)
  			break;
  	}
  	if (&req->req != _req) {
  		spin_unlock_irqrestore (&ep->dev->lock, flags);
  		return -EINVAL;
  	}
  
  	/* queue head may be partially complete. */
  	if (ep->queue.next == &req->queue) {
  		if (ep->dma) {
  			DEBUG (ep->dev, "unlink (%s) dma\n", _ep->name);
  			_req->status = -ECONNRESET;
  			abort_dma (ep);
  			if (likely (ep->queue.next == &req->queue)) {
  				// NOTE: misreports single-transfer mode
  				req->td->dmacount = 0;	/* invalidate */
  				dma_done (ep, req,
  					readl (&ep->dma->dmacount),
  					-ECONNRESET);
  			}
  		} else {
  			DEBUG (ep->dev, "unlink (%s) pio\n", _ep->name);
  			done (ep, req, -ECONNRESET);
  		}
  		req = NULL;
  
  	/* patch up hardware chaining data */
  	} else if (ep->dma && use_dma_chaining) {
  		if (req->queue.prev == ep->queue.next) {
  			writel (le32_to_cpu (req->td->dmadesc),
  				&ep->dma->dmadesc);
  			if (req->td->dmacount & dma_done_ie)
  				writel (readl (&ep->dma->dmacount)
  						| le32_to_cpu(dma_done_ie),
  					&ep->dma->dmacount);
  		} else {
  			struct net2280_request	*prev;
  
  			prev = list_entry (req->queue.prev,
  				struct net2280_request, queue);
  			prev->td->dmadesc = req->td->dmadesc;
  			if (req->td->dmacount & dma_done_ie)
  				prev->td->dmacount |= dma_done_ie;
  		}
  	}
  
  	if (req)
  		done (ep, req, -ECONNRESET);
  	ep->stopped = stopped;
  
  	if (ep->dma) {
  		/* turn off dma on inactive queues */
  		if (list_empty (&ep->queue))
  			stop_dma (ep->dma);
  		else if (!ep->stopped) {
  			/* resume current request, or start new one */
  			if (req)
  				writel (dmactl, &ep->dma->dmactl);
  			else
  				start_dma (ep, list_entry (ep->queue.next,
  					struct net2280_request, queue));
  		}
  	}
  
  	spin_unlock_irqrestore (&ep->dev->lock, flags);
  	return 0;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static int net2280_fifo_status (struct usb_ep *_ep);
  
  static int
  net2280_set_halt_and_wedge(struct usb_ep *_ep, int value, int wedged)
  {
  	struct net2280_ep	*ep;
  	unsigned long		flags;
  	int			retval = 0;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || (!ep->desc && ep->num != 0))
  		return -EINVAL;
  	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
  		return -ESHUTDOWN;
  	if (ep->desc /* not ep0 */ && (ep->desc->bmAttributes & 0x03)
  						== USB_ENDPOINT_XFER_ISOC)
  		return -EINVAL;
  
  	spin_lock_irqsave (&ep->dev->lock, flags);
  	if (!list_empty (&ep->queue))
  		retval = -EAGAIN;
  	else if (ep->is_in && value && net2280_fifo_status (_ep) != 0)
  		retval = -EAGAIN;
  	else {
  		VDEBUG (ep->dev, "%s %s %s\n", _ep->name,
  				value ? "set" : "clear",
  				wedged ? "wedge" : "halt");
  		/* set/clear, then synch memory views with the device */
  		if (value) {
  			if (ep->num == 0)
  				ep->dev->protocol_stall = 1;
  			else
  				set_halt (ep);
  			if (wedged)
  				ep->wedged = 1;
  		} else {
  			clear_halt (ep);
  			ep->wedged = 0;
  		}
  		(void) readl (&ep->regs->ep_rsp);
  	}
  	spin_unlock_irqrestore (&ep->dev->lock, flags);
  
  	return retval;
  }
  
  static int
  net2280_set_halt(struct usb_ep *_ep, int value)
  {
  	return net2280_set_halt_and_wedge(_ep, value, 0);
  }
  
  static int
  net2280_set_wedge(struct usb_ep *_ep)
  {
  	if (!_ep || _ep->name == ep0name)
  		return -EINVAL;
  	return net2280_set_halt_and_wedge(_ep, 1, 1);
  }
  
  static int
  net2280_fifo_status (struct usb_ep *_ep)
  {
  	struct net2280_ep	*ep;
  	u32			avail;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || (!ep->desc && ep->num != 0))
  		return -ENODEV;
  	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
  		return -ESHUTDOWN;
  
  	avail = readl (&ep->regs->ep_avail) & ((1 << 12) - 1);
  	if (avail > ep->fifo_size)
  		return -EOVERFLOW;
  	if (ep->is_in)
  		avail = ep->fifo_size - avail;
  	return avail;
  }
  
  static void
  net2280_fifo_flush (struct usb_ep *_ep)
  {
  	struct net2280_ep	*ep;
  
  	ep = container_of (_ep, struct net2280_ep, ep);
  	if (!_ep || (!ep->desc && ep->num != 0))
  		return;
  	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
  		return;
  
  	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
  	(void) readl (&ep->regs->ep_rsp);
  }
  
  static const struct usb_ep_ops net2280_ep_ops = {
  	.enable		= net2280_enable,
  	.disable	= net2280_disable,
  
  	.alloc_request	= net2280_alloc_request,
  	.free_request	= net2280_free_request,
  
  	.queue		= net2280_queue,
  	.dequeue	= net2280_dequeue,
  
  	.set_halt	= net2280_set_halt,
  	.set_wedge	= net2280_set_wedge,
  	.fifo_status	= net2280_fifo_status,
  	.fifo_flush	= net2280_fifo_flush,
  };
  
  /*-------------------------------------------------------------------------*/
  
  static int net2280_get_frame (struct usb_gadget *_gadget)
  {
  	struct net2280		*dev;
  	unsigned long		flags;
  	u16			retval;
  
  	if (!_gadget)
  		return -ENODEV;
  	dev = container_of (_gadget, struct net2280, gadget);
  	spin_lock_irqsave (&dev->lock, flags);
  	retval = get_idx_reg (dev->regs, REG_FRAME) & 0x03ff;
  	spin_unlock_irqrestore (&dev->lock, flags);
  	return retval;
  }
  
  static int net2280_wakeup (struct usb_gadget *_gadget)
  {
  	struct net2280		*dev;
  	u32			tmp;
  	unsigned long		flags;
  
  	if (!_gadget)
  		return 0;
  	dev = container_of (_gadget, struct net2280, gadget);
  
  	spin_lock_irqsave (&dev->lock, flags);
  	tmp = readl (&dev->usb->usbctl);
  	if (tmp & (1 << DEVICE_REMOTE_WAKEUP_ENABLE))
  		writel (1 << GENERATE_RESUME, &dev->usb->usbstat);
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	/* pci writes may still be posted */
  	return 0;
  }
  
  static int net2280_set_selfpowered (struct usb_gadget *_gadget, int value)
  {
  	struct net2280		*dev;
  	u32			tmp;
  	unsigned long		flags;
  
  	if (!_gadget)
  		return 0;
  	dev = container_of (_gadget, struct net2280, gadget);
  
  	spin_lock_irqsave (&dev->lock, flags);
  	tmp = readl (&dev->usb->usbctl);
  	if (value)
  		tmp |= (1 << SELF_POWERED_STATUS);
  	else
  		tmp &= ~(1 << SELF_POWERED_STATUS);
  	writel (tmp, &dev->usb->usbctl);
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	return 0;
  }
  
  static int net2280_pullup(struct usb_gadget *_gadget, int is_on)
  {
  	struct net2280  *dev;
  	u32             tmp;
  	unsigned long   flags;
  
  	if (!_gadget)
  		return -ENODEV;
  	dev = container_of (_gadget, struct net2280, gadget);
  
  	spin_lock_irqsave (&dev->lock, flags);
  	tmp = readl (&dev->usb->usbctl);
  	dev->softconnect = (is_on != 0);
  	if (is_on)
  		tmp |= (1 << USB_DETECT_ENABLE);
  	else
  		tmp &= ~(1 << USB_DETECT_ENABLE);
  	writel (tmp, &dev->usb->usbctl);
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	return 0;
  }
  
  static int net2280_start(struct usb_gadget *_gadget,
  		struct usb_gadget_driver *driver);
  static int net2280_stop(struct usb_gadget *_gadget,
  		struct usb_gadget_driver *driver);
  
  static const struct usb_gadget_ops net2280_ops = {
  	.get_frame	= net2280_get_frame,
  	.wakeup		= net2280_wakeup,
  	.set_selfpowered = net2280_set_selfpowered,
  	.pullup		= net2280_pullup,
  	.udc_start	= net2280_start,
  	.udc_stop	= net2280_stop,
  };
  
  /*-------------------------------------------------------------------------*/
  
  #ifdef	CONFIG_USB_GADGET_DEBUG_FILES
  
  /* FIXME move these into procfs, and use seq_file.
   * Sysfs _still_ doesn't behave for arbitrarily sized files,
   * and also doesn't help products using this with 2.4 kernels.
   */
  
  /* "function" sysfs attribute */
  static ssize_t
  show_function (struct device *_dev, struct device_attribute *attr, char *buf)
  {
  	struct net2280	*dev = dev_get_drvdata (_dev);
  
  	if (!dev->driver
  			|| !dev->driver->function
  			|| strlen (dev->driver->function) > PAGE_SIZE)
  		return 0;
  	return scnprintf (buf, PAGE_SIZE, "%s\n", dev->driver->function);
  }
  static DEVICE_ATTR (function, S_IRUGO, show_function, NULL);
  
  static ssize_t net2280_show_registers(struct device *_dev,
  				struct device_attribute *attr, char *buf)
  {
  	struct net2280		*dev;
  	char			*next;
  	unsigned		size, t;
  	unsigned long		flags;
  	int			i;
  	u32			t1, t2;
  	const char		*s;
  
  	dev = dev_get_drvdata (_dev);
  	next = buf;
  	size = PAGE_SIZE;
  	spin_lock_irqsave (&dev->lock, flags);
  
  	if (dev->driver)
  		s = dev->driver->driver.name;
  	else
  		s = "(none)";
  
  	/* Main Control Registers */
  	t = scnprintf (next, size, "%s version " DRIVER_VERSION
  			", chiprev %04x, dma %s\n\n"
  			"devinit %03x fifoctl %08x gadget '%s'\n"
  			"pci irqenb0 %02x irqenb1 %08x "
  			"irqstat0 %04x irqstat1 %08x\n",
  			driver_name, dev->chiprev,
  			use_dma
  				? (use_dma_chaining ? "chaining" : "enabled")
  				: "disabled",
  			readl (&dev->regs->devinit),
  			readl (&dev->regs->fifoctl),
  			s,
  			readl (&dev->regs->pciirqenb0),
  			readl (&dev->regs->pciirqenb1),
  			readl (&dev->regs->irqstat0),
  			readl (&dev->regs->irqstat1));
  	size -= t;
  	next += t;
  
  	/* USB Control Registers */
  	t1 = readl (&dev->usb->usbctl);
  	t2 = readl (&dev->usb->usbstat);
  	if (t1 & (1 << VBUS_PIN)) {
  		if (t2 & (1 << HIGH_SPEED))
  			s = "high speed";
  		else if (dev->gadget.speed == USB_SPEED_UNKNOWN)
  			s = "powered";
  		else
  			s = "full speed";
  		/* full speed bit (6) not working?? */
  	} else
  			s = "not attached";
  	t = scnprintf (next, size,
  			"stdrsp %08x usbctl %08x usbstat %08x "
  				"addr 0x%02x (%s)\n",
  			readl (&dev->usb->stdrsp), t1, t2,
  			readl (&dev->usb->ouraddr), s);
  	size -= t;
  	next += t;
  
  	/* PCI Master Control Registers */
  
  	/* DMA Control Registers */
  
  	/* Configurable EP Control Registers */
  	for (i = 0; i < 7; i++) {
  		struct net2280_ep	*ep;
  
  		ep = &dev->ep [i];
  		if (i && !ep->desc)
  			continue;
  
  		t1 = readl (&ep->regs->ep_cfg);
  		t2 = readl (&ep->regs->ep_rsp) & 0xff;
  		t = scnprintf (next, size,
  				"\n%s\tcfg %05x rsp (%02x) %s%s%s%s%s%s%s%s"
  					"irqenb %02x\n",
  				ep->ep.name, t1, t2,
  				(t2 & (1 << CLEAR_NAK_OUT_PACKETS))
  					? "NAK " : "",
  				(t2 & (1 << CLEAR_EP_HIDE_STATUS_PHASE))
  					? "hide " : "",
  				(t2 & (1 << CLEAR_EP_FORCE_CRC_ERROR))
  					? "CRC " : "",
  				(t2 & (1 << CLEAR_INTERRUPT_MODE))
  					? "interrupt " : "",
  				(t2 & (1<<CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE))
  					? "status " : "",
  				(t2 & (1 << CLEAR_NAK_OUT_PACKETS_MODE))
  					? "NAKmode " : "",
  				(t2 & (1 << CLEAR_ENDPOINT_TOGGLE))
  					? "DATA1 " : "DATA0 ",
  				(t2 & (1 << CLEAR_ENDPOINT_HALT))
  					? "HALT " : "",
  				readl (&ep->regs->ep_irqenb));
  		size -= t;
  		next += t;
  
  		t = scnprintf (next, size,
  				"\tstat %08x avail %04x "
  				"(ep%d%s-%s)%s\n",
  				readl (&ep->regs->ep_stat),
  				readl (&ep->regs->ep_avail),
  				t1 & 0x0f, DIR_STRING (t1),
  				type_string (t1 >> 8),
  				ep->stopped ? "*" : "");
  		size -= t;
  		next += t;
  
  		if (!ep->dma)
  			continue;
  
  		t = scnprintf (next, size,
  				"  dma\tctl %08x stat %08x count %08x\n"
  				"\taddr %08x desc %08x\n",
  				readl (&ep->dma->dmactl),
  				readl (&ep->dma->dmastat),
  				readl (&ep->dma->dmacount),
  				readl (&ep->dma->dmaaddr),
  				readl (&ep->dma->dmadesc));
  		size -= t;
  		next += t;
  
  	}
  
  	/* Indexed Registers */
  		// none yet
  
  	/* Statistics */
  	t = scnprintf (next, size, "\nirqs:  ");
  	size -= t;
  	next += t;
  	for (i = 0; i < 7; i++) {
  		struct net2280_ep	*ep;
  
  		ep = &dev->ep [i];
  		if (i && !ep->irqs)
  			continue;
  		t = scnprintf (next, size, " %s/%lu", ep->ep.name, ep->irqs);
  		size -= t;
  		next += t;
  
  	}
  	t = scnprintf (next, size, "\n");
  	size -= t;
  	next += t;
  
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	return PAGE_SIZE - size;
  }
  static DEVICE_ATTR(registers, S_IRUGO, net2280_show_registers, NULL);
  
  static ssize_t
  show_queues (struct device *_dev, struct device_attribute *attr, char *buf)
  {
  	struct net2280		*dev;
  	char			*next;
  	unsigned		size;
  	unsigned long		flags;
  	int			i;
  
  	dev = dev_get_drvdata (_dev);
  	next = buf;
  	size = PAGE_SIZE;
  	spin_lock_irqsave (&dev->lock, flags);
  
  	for (i = 0; i < 7; i++) {
  		struct net2280_ep		*ep = &dev->ep [i];
  		struct net2280_request		*req;
  		int				t;
  
  		if (i != 0) {
  			const struct usb_endpoint_descriptor	*d;
  
  			d = ep->desc;
  			if (!d)
  				continue;
  			t = d->bEndpointAddress;
  			t = scnprintf (next, size,
  				"\n%s (ep%d%s-%s) max %04x %s fifo %d\n",
  				ep->ep.name, t & USB_ENDPOINT_NUMBER_MASK,
  				(t & USB_DIR_IN) ? "in" : "out",
  				({ char *val;
  				 switch (d->bmAttributes & 0x03) {
  				 case USB_ENDPOINT_XFER_BULK:
  					val = "bulk"; break;
  				 case USB_ENDPOINT_XFER_INT:
  					val = "intr"; break;
  				 default:
  					val = "iso"; break;
  				 }; val; }),
  				usb_endpoint_maxp (d) & 0x1fff,
  				ep->dma ? "dma" : "pio", ep->fifo_size
  				);
  		} else /* ep0 should only have one transfer queued */
  			t = scnprintf (next, size, "ep0 max 64 pio %s\n",
  					ep->is_in ? "in" : "out");
  		if (t <= 0 || t > size)
  			goto done;
  		size -= t;
  		next += t;
  
  		if (list_empty (&ep->queue)) {
  			t = scnprintf (next, size, "\t(nothing queued)\n");
  			if (t <= 0 || t > size)
  				goto done;
  			size -= t;
  			next += t;
  			continue;
  		}
  		list_for_each_entry (req, &ep->queue, queue) {
  			if (ep->dma && req->td_dma == readl (&ep->dma->dmadesc))
  				t = scnprintf (next, size,
  					"\treq %p len %d/%d "
  					"buf %p (dmacount %08x)\n",
  					&req->req, req->req.actual,
  					req->req.length, req->req.buf,
  					readl (&ep->dma->dmacount));
  			else
  				t = scnprintf (next, size,
  					"\treq %p len %d/%d buf %p\n",
  					&req->req, req->req.actual,
  					req->req.length, req->req.buf);
  			if (t <= 0 || t > size)
  				goto done;
  			size -= t;
  			next += t;
  
  			if (ep->dma) {
  				struct net2280_dma	*td;
  
  				td = req->td;
  				t = scnprintf (next, size, "\t    td %08x "
  					" count %08x buf %08x desc %08x\n",
  					(u32) req->td_dma,
  					le32_to_cpu (td->dmacount),
  					le32_to_cpu (td->dmaaddr),
  					le32_to_cpu (td->dmadesc));
  				if (t <= 0 || t > size)
  					goto done;
  				size -= t;
  				next += t;
  			}
  		}
  	}
  
  done:
  	spin_unlock_irqrestore (&dev->lock, flags);
  	return PAGE_SIZE - size;
  }
  static DEVICE_ATTR (queues, S_IRUGO, show_queues, NULL);
  
  
  #else
  
  #define device_create_file(a,b)	(0)
  #define device_remove_file(a,b)	do { } while (0)
  
  #endif
  
  /*-------------------------------------------------------------------------*/
  
  /* another driver-specific mode might be a request type doing dma
   * to/from another device fifo instead of to/from memory.
   */
  
  static void set_fifo_mode (struct net2280 *dev, int mode)
  {
  	/* keeping high bits preserves BAR2 */
  	writel ((0xffff << PCI_BASE2_RANGE) | mode, &dev->regs->fifoctl);
  
  	/* always ep-{a,b,e,f} ... maybe not ep-c or ep-d */
  	INIT_LIST_HEAD (&dev->gadget.ep_list);
  	list_add_tail (&dev->ep [1].ep.ep_list, &dev->gadget.ep_list);
  	list_add_tail (&dev->ep [2].ep.ep_list, &dev->gadget.ep_list);
  	switch (mode) {
  	case 0:
  		list_add_tail (&dev->ep [3].ep.ep_list, &dev->gadget.ep_list);
  		list_add_tail (&dev->ep [4].ep.ep_list, &dev->gadget.ep_list);
  		dev->ep [1].fifo_size = dev->ep [2].fifo_size = 1024;
  		break;
  	case 1:
  		dev->ep [1].fifo_size = dev->ep [2].fifo_size = 2048;
  		break;
  	case 2:
  		list_add_tail (&dev->ep [3].ep.ep_list, &dev->gadget.ep_list);
  		dev->ep [1].fifo_size = 2048;
  		dev->ep [2].fifo_size = 1024;
  		break;
  	}
  	/* fifo sizes for ep0, ep-c, ep-d, ep-e, and ep-f never change */
  	list_add_tail (&dev->ep [5].ep.ep_list, &dev->gadget.ep_list);
  	list_add_tail (&dev->ep [6].ep.ep_list, &dev->gadget.ep_list);
  }
  
  /* keeping it simple:
   * - one bus driver, initted first;
   * - one function driver, initted second
   *
   * most of the work to support multiple net2280 controllers would
   * be to associate this gadget driver (yes?) with all of them, or
   * perhaps to bind specific drivers to specific devices.
   */
  
  static void usb_reset (struct net2280 *dev)
  {
  	u32	tmp;
  
  	dev->gadget.speed = USB_SPEED_UNKNOWN;
  	(void) readl (&dev->usb->usbctl);
  
  	net2280_led_init (dev);
  
  	/* disable automatic responses, and irqs */
  	writel (0, &dev->usb->stdrsp);
  	writel (0, &dev->regs->pciirqenb0);
  	writel (0, &dev->regs->pciirqenb1);
  
  	/* clear old dma and irq state */
  	for (tmp = 0; tmp < 4; tmp++) {
  		struct net2280_ep	*ep = &dev->ep [tmp + 1];
  
  		if (ep->dma)
  			abort_dma (ep);
  	}
  	writel (~0, &dev->regs->irqstat0),
  	writel (~(1 << SUSPEND_REQUEST_INTERRUPT), &dev->regs->irqstat1),
  
  	/* reset, and enable pci */
  	tmp = readl (&dev->regs->devinit)
  		| (1 << PCI_ENABLE)
  		| (1 << FIFO_SOFT_RESET)
  		| (1 << USB_SOFT_RESET)
  		| (1 << M8051_RESET);
  	writel (tmp, &dev->regs->devinit);
  
  	/* standard fifo and endpoint allocations */
  	set_fifo_mode (dev, (fifo_mode <= 2) ? fifo_mode : 0);
  }
  
  static void usb_reinit (struct net2280 *dev)
  {
  	u32	tmp;
  	int	init_dma;
  
  	/* use_dma changes are ignored till next device re-init */
  	init_dma = use_dma;
  
  	/* basic endpoint init */
  	for (tmp = 0; tmp < 7; tmp++) {
  		struct net2280_ep	*ep = &dev->ep [tmp];
  
  		ep->ep.name = ep_name [tmp];
  		ep->dev = dev;
  		ep->num = tmp;
  
  		if (tmp > 0 && tmp <= 4) {
  			ep->fifo_size = 1024;
  			if (init_dma)
  				ep->dma = &dev->dma [tmp - 1];
  		} else
  			ep->fifo_size = 64;
  		ep->regs = &dev->epregs [tmp];
  		ep_reset (dev->regs, ep);
  	}
  	dev->ep [0].ep.maxpacket = 64;
  	dev->ep [5].ep.maxpacket = 64;
  	dev->ep [6].ep.maxpacket = 64;
  
  	dev->gadget.ep0 = &dev->ep [0].ep;
  	dev->ep [0].stopped = 0;
  	INIT_LIST_HEAD (&dev->gadget.ep0->ep_list);
  
  	/* we want to prevent lowlevel/insecure access from the USB host,
  	 * but erratum 0119 means this enable bit is ignored
  	 */
  	for (tmp = 0; tmp < 5; tmp++)
  		writel (EP_DONTUSE, &dev->dep [tmp].dep_cfg);
  }
  
  static void ep0_start (struct net2280 *dev)
  {
  	writel (  (1 << CLEAR_EP_HIDE_STATUS_PHASE)
  		| (1 << CLEAR_NAK_OUT_PACKETS)
  		| (1 << CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE)
  		, &dev->epregs [0].ep_rsp);
  
  	/*
  	 * hardware optionally handles a bunch of standard requests
  	 * that the API hides from drivers anyway.  have it do so.
  	 * endpoint status/features are handled in software, to
  	 * help pass tests for some dubious behavior.
  	 */
  	writel (  (1 << SET_TEST_MODE)
  		| (1 << SET_ADDRESS)
  		| (1 << DEVICE_SET_CLEAR_DEVICE_REMOTE_WAKEUP)
  		| (1 << GET_DEVICE_STATUS)
  		| (1 << GET_INTERFACE_STATUS)
  		, &dev->usb->stdrsp);
  	writel (  (1 << USB_ROOT_PORT_WAKEUP_ENABLE)
  		| (1 << SELF_POWERED_USB_DEVICE)
  		| (1 << REMOTE_WAKEUP_SUPPORT)
  		| (dev->softconnect << USB_DETECT_ENABLE)
  		| (1 << SELF_POWERED_STATUS)
  		, &dev->usb->usbctl);
  
  	/* enable irqs so we can see ep0 and general operation  */
  	writel (  (1 << SETUP_PACKET_INTERRUPT_ENABLE)
  		| (1 << ENDPOINT_0_INTERRUPT_ENABLE)
  		, &dev->regs->pciirqenb0);
  	writel (  (1 << PCI_INTERRUPT_ENABLE)
  		| (1 << PCI_MASTER_ABORT_RECEIVED_INTERRUPT_ENABLE)
  		| (1 << PCI_TARGET_ABORT_RECEIVED_INTERRUPT_ENABLE)
  		| (1 << PCI_RETRY_ABORT_INTERRUPT_ENABLE)
  		| (1 << VBUS_INTERRUPT_ENABLE)
  		| (1 << ROOT_PORT_RESET_INTERRUPT_ENABLE)
  		| (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE)
  		, &dev->regs->pciirqenb1);
  
  	/* don't leave any writes posted */
  	(void) readl (&dev->usb->usbctl);
  }
  
  /* when a driver is successfully registered, it will receive
   * control requests including set_configuration(), which enables
   * non-control requests.  then usb traffic follows until a
   * disconnect is reported.  then a host may connect again, or
   * the driver might get unbound.
   */
  static int net2280_start(struct usb_gadget *_gadget,
  		struct usb_gadget_driver *driver)
  {
  	struct net2280		*dev;
  	int			retval;
  	unsigned		i;
  
  	/* insist on high speed support from the driver, since
  	 * (dev->usb->xcvrdiag & FORCE_FULL_SPEED_MODE)
  	 * "must not be used in normal operation"
  	 */
  	if (!driver || driver->max_speed < USB_SPEED_HIGH
  			|| !driver->setup)
  		return -EINVAL;
  
  	dev = container_of (_gadget, struct net2280, gadget);
  
  	for (i = 0; i < 7; i++)
  		dev->ep [i].irqs = 0;
  
  	/* hook up the driver ... */
  	dev->softconnect = 1;
  	driver->driver.bus = NULL;
  	dev->driver = driver;
  	dev->gadget.dev.driver = &driver->driver;
  
  	retval = device_create_file (&dev->pdev->dev, &dev_attr_function);
  	if (retval) goto err_unbind;
  	retval = device_create_file (&dev->pdev->dev, &dev_attr_queues);
  	if (retval) goto err_func;
  
  	/* ... then enable host detection and ep0; and we're ready
  	 * for set_configuration as well as eventual disconnect.
  	 */
  	net2280_led_active (dev, 1);
  	ep0_start (dev);
  
  	DEBUG (dev, "%s ready, usbctl %08x stdrsp %08x\n",
  			driver->driver.name,
  			readl (&dev->usb->usbctl),
  			readl (&dev->usb->stdrsp));
  
  	/* pci writes may still be posted */
  	return 0;
  
  err_func:
  	device_remove_file (&dev->pdev->dev, &dev_attr_function);
  err_unbind:
  	driver->unbind (&dev->gadget);
  	dev->gadget.dev.driver = NULL;
  	dev->driver = NULL;
  	return retval;
  }
  
  static void
  stop_activity (struct net2280 *dev, struct usb_gadget_driver *driver)
  {
  	int			i;
  
  	/* don't disconnect if it's not connected */
  	if (dev->gadget.speed == USB_SPEED_UNKNOWN)
  		driver = NULL;
  
  	/* stop hardware; prevent new request submissions;
  	 * and kill any outstanding requests.
  	 */
  	usb_reset (dev);
  	for (i = 0; i < 7; i++)
  		nuke (&dev->ep [i]);
  
  	usb_reinit (dev);
  }
  
  static int net2280_stop(struct usb_gadget *_gadget,
  		struct usb_gadget_driver *driver)
  {
  	struct net2280	*dev;
  	unsigned long	flags;
  
  	dev = container_of (_gadget, struct net2280, gadget);
  
  	spin_lock_irqsave (&dev->lock, flags);
  	stop_activity (dev, driver);
  	spin_unlock_irqrestore (&dev->lock, flags);
  
  	dev->gadget.dev.driver = NULL;
  	dev->driver = NULL;
  
  	net2280_led_active (dev, 0);
  	device_remove_file (&dev->pdev->dev, &dev_attr_function);
  	device_remove_file (&dev->pdev->dev, &dev_attr_queues);
  
  	DEBUG (dev, "unregistered driver '%s'\n", driver->driver.name);
  	return 0;
  }
  
  /*-------------------------------------------------------------------------*/
  
  /* handle ep0, ep-e, ep-f with 64 byte packets: packet per irq.
   * also works for dma-capable endpoints, in pio mode or just
   * to manually advance the queue after short OUT transfers.
   */
  static void handle_ep_small (struct net2280_ep *ep)
  {
  	struct net2280_request	*req;
  	u32			t;
  	/* 0 error, 1 mid-data, 2 done */
  	int			mode = 1;
  
  	if (!list_empty (&ep->queue))
  		req = list_entry (ep->queue.next,
  			struct net2280_request, queue);
  	else
  		req = NULL;
  
  	/* ack all, and handle what we care about */
  	t = readl (&ep->regs->ep_stat);
  	ep->irqs++;
  #if 0
  	VDEBUG (ep->dev, "%s ack ep_stat %08x, req %p\n",
  			ep->ep.name, t, req ? &req->req : 0);
  #endif
  	if (!ep->is_in || ep->dev->pdev->device == 0x2280)
  		writel (t & ~(1 << NAK_OUT_PACKETS), &ep->regs->ep_stat);
  	else
  		/* Added for 2282 */
  		writel (t, &ep->regs->ep_stat);
  
  	/* for ep0, monitor token irqs to catch data stage length errors
  	 * and to synchronize on status.
  	 *
  	 * also, to defer reporting of protocol stalls ... here's where
  	 * data or status first appears, handling stalls here should never
  	 * cause trouble on the host side..
  	 *
  	 * control requests could be slightly faster without token synch for
  	 * status, but status can jam up that way.
  	 */
  	if (unlikely (ep->num == 0)) {
  		if (ep->is_in) {
  			/* status; stop NAKing */
  			if (t & (1 << DATA_OUT_PING_TOKEN_INTERRUPT)) {
  				if (ep->dev->protocol_stall) {
  					ep->stopped = 1;
  					set_halt (ep);
  				}
  				if (!req)
  					allow_status (ep);
  				mode = 2;
  			/* reply to extra IN data tokens with a zlp */
  			} else if (t & (1 << DATA_IN_TOKEN_INTERRUPT)) {
  				if (ep->dev->protocol_stall) {
  					ep->stopped = 1;
  					set_halt (ep);
  					mode = 2;
  				} else if (ep->responded &&
  						!req && !ep->stopped)
  					write_fifo (ep, NULL);
  			}
  		} else {
  			/* status; stop NAKing */
  			if (t & (1 << DATA_IN_TOKEN_INTERRUPT)) {
  				if (ep->dev->protocol_stall) {
  					ep->stopped = 1;
  					set_halt (ep);
  				}
  				mode = 2;
  			/* an extra OUT token is an error */
  			} else if (((t & (1 << DATA_OUT_PING_TOKEN_INTERRUPT))
  					&& req
  					&& req->req.actual == req->req.length)
  					|| (ep->responded && !req)) {
  				ep->dev->protocol_stall = 1;
  				set_halt (ep);
  				ep->stopped = 1;
  				if (req)
  					done (ep, req, -EOVERFLOW);
  				req = NULL;
  			}
  		}
  	}
  
  	if (unlikely (!req))
  		return;
  
  	/* manual DMA queue advance after short OUT */
  	if (likely (ep->dma != 0)) {
  		if (t & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)) {
  			u32	count;
  			int	stopped = ep->stopped;
  
  			/* TRANSFERRED works around OUT_DONE erratum 0112.
  			 * we expect (N <= maxpacket) bytes; host wrote M.
  			 * iff (M < N) we won't ever see a DMA interrupt.
  			 */
  			ep->stopped = 1;
  			for (count = 0; ; t = readl (&ep->regs->ep_stat)) {
  
  				/* any preceding dma transfers must finish.
  				 * dma handles (M >= N), may empty the queue
  				 */
  				scan_dma_completions (ep);
  				if (unlikely (list_empty (&ep->queue)
  						|| ep->out_overflow)) {
  					req = NULL;
  					break;
  				}
  				req = list_entry (ep->queue.next,
  					struct net2280_request, queue);
  
  				/* here either (M < N), a "real" short rx;
  				 * or (M == N) and the queue didn't empty
  				 */
  				if (likely (t & (1 << FIFO_EMPTY))) {
  					count = readl (&ep->dma->dmacount);
  					count &= DMA_BYTE_COUNT_MASK;
  					if (readl (&ep->dma->dmadesc)
  							!= req->td_dma)
  						req = NULL;
  					break;
  				}
  				udelay(1);
  			}
  
  			/* stop DMA, leave ep NAKing */
  			writel ((1 << DMA_ABORT), &ep->dma->dmastat);
  			spin_stop_dma (ep->dma);
  
  			if (likely (req)) {
  				req->td->dmacount = 0;
  				t = readl (&ep->regs->ep_avail);
  				dma_done (ep, req, count,
  					(ep->out_overflow || t)
  						? -EOVERFLOW : 0);
  			}
  
  			/* also flush to prevent erratum 0106 trouble */
  			if (unlikely (ep->out_overflow
  					|| (ep->dev->chiprev == 0x0100
  						&& ep->dev->gadget.speed
  							== USB_SPEED_FULL))) {
  				out_flush (ep);
  				ep->out_overflow = 0;
  			}
  
  			/* (re)start dma if needed, stop NAKing */
  			ep->stopped = stopped;
  			if (!list_empty (&ep->queue))
  				restart_dma (ep);
  		} else
  			DEBUG (ep->dev, "%s dma ep_stat %08x ??\n",
  					ep->ep.name, t);
  		return;
  
  	/* data packet(s) received (in the fifo, OUT) */
  	} else if (t & (1 << DATA_PACKET_RECEIVED_INTERRUPT)) {
  		if (read_fifo (ep, req) && ep->num != 0)
  			mode = 2;
  
  	/* data packet(s) transmitted (IN) */
  	} else if (t & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)) {
  		unsigned	len;
  
  		len = req->req.length - req->req.actual;
  		if (len > ep->ep.maxpacket)
  			len = ep->ep.maxpacket;
  		req->req.actual += len;
  
  		/* if we wrote it all, we're usually done */
  		if (req->req.actual == req->req.length) {
  			if (ep->num == 0) {
  				/* send zlps until the status stage */
  			} else if (!req->req.zero || len != ep->ep.maxpacket)
  				mode = 2;
  		}
  
  	/* there was nothing to do ...  */
  	} else if (mode == 1)
  		return;
  
  	/* done */
  	if (mode == 2) {
  		/* stream endpoints often resubmit/unlink in completion */
  		done (ep, req, 0);
  
  		/* maybe advance queue to next request */
  		if (ep->num == 0) {
  			/* NOTE:  net2280 could let gadget driver start the
  			 * status stage later. since not all controllers let
  			 * them control that, the api doesn't (yet) allow it.
  			 */
  			if (!ep->stopped)
  				allow_status (ep);
  			req = NULL;
  		} else {
  			if (!list_empty (&ep->queue) && !ep->stopped)
  				req = list_entry (ep->queue.next,
  					struct net2280_request, queue);
  			else
  				req = NULL;
  			if (req && !ep->is_in)
  				stop_out_naking (ep);
  		}
  	}
  
  	/* is there a buffer for the next packet?
  	 * for best streaming performance, make sure there is one.
  	 */
  	if (req && !ep->stopped) {
  
  		/* load IN fifo with next packet (may be zlp) */
  		if (t & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT))
  			write_fifo (ep, &req->req);
  	}
  }
  
  static struct net2280_ep *
  get_ep_by_addr (struct net2280 *dev, u16 wIndex)
  {
  	struct net2280_ep	*ep;
  
  	if ((wIndex & USB_ENDPOINT_NUMBER_MASK) == 0)
  		return &dev->ep [0];
  	list_for_each_entry (ep, &dev->gadget.ep_list, ep.ep_list) {
  		u8	bEndpointAddress;
  
  		if (!ep->desc)
  			continue;
  		bEndpointAddress = ep->desc->bEndpointAddress;
  		if ((wIndex ^ bEndpointAddress) & USB_DIR_IN)
  			continue;
  		if ((wIndex & 0x0f) == (bEndpointAddress & 0x0f))
  			return ep;
  	}
  	return NULL;
  }
  
  static void handle_stat0_irqs (struct net2280 *dev, u32 stat)
  {
  	struct net2280_ep	*ep;
  	u32			num, scratch;
  
  	/* most of these don't need individual acks */
  	stat &= ~(1 << INTA_ASSERTED);
  	if (!stat)
  		return;
  	// DEBUG (dev, "irqstat0 %04x\n", stat);
  
  	/* starting a control request? */
  	if (unlikely (stat & (1 << SETUP_PACKET_INTERRUPT))) {
  		union {
  			u32			raw [2];
  			struct usb_ctrlrequest	r;
  		} u;
  		int				tmp;
  		struct net2280_request		*req;
  
  		if (dev->gadget.speed == USB_SPEED_UNKNOWN) {
  			if (readl (&dev->usb->usbstat) & (1 << HIGH_SPEED))
  				dev->gadget.speed = USB_SPEED_HIGH;
  			else
  				dev->gadget.speed = USB_SPEED_FULL;
  			net2280_led_speed (dev, dev->gadget.speed);
  			DEBUG(dev, "%s\n", usb_speed_string(dev->gadget.speed));
  		}
  
  		ep = &dev->ep [0];
  		ep->irqs++;
  
  		/* make sure any leftover request state is cleared */
  		stat &= ~(1 << ENDPOINT_0_INTERRUPT);
  		while (!list_empty (&ep->queue)) {
  			req = list_entry (ep->queue.next,
  					struct net2280_request, queue);
  			done (ep, req, (req->req.actual == req->req.length)
  						? 0 : -EPROTO);
  		}
  		ep->stopped = 0;
  		dev->protocol_stall = 0;
  
  		if (ep->dev->pdev->device == 0x2280)
  			tmp = (1 << FIFO_OVERFLOW)
  				| (1 << FIFO_UNDERFLOW);
  		else
  			tmp = 0;
  
  		writel (tmp | (1 << TIMEOUT)
  			| (1 << USB_STALL_SENT)
  			| (1 << USB_IN_NAK_SENT)
  			| (1 << USB_IN_ACK_RCVD)
  			| (1 << USB_OUT_PING_NAK_SENT)
  			| (1 << USB_OUT_ACK_SENT)
  			| (1 << SHORT_PACKET_OUT_DONE_INTERRUPT)
  			| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)
  			| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
  			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
  			| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  			| (1 << DATA_IN_TOKEN_INTERRUPT)
  			, &ep->regs->ep_stat);
  		u.raw [0] = readl (&dev->usb->setup0123);
  		u.raw [1] = readl (&dev->usb->setup4567);
  
  		cpu_to_le32s (&u.raw [0]);
  		cpu_to_le32s (&u.raw [1]);
  
  		tmp = 0;
  
  #define	w_value		le16_to_cpu(u.r.wValue)
  #define	w_index		le16_to_cpu(u.r.wIndex)
  #define	w_length	le16_to_cpu(u.r.wLength)
  
  		/* ack the irq */
  		writel (1 << SETUP_PACKET_INTERRUPT, &dev->regs->irqstat0);
  		stat ^= (1 << SETUP_PACKET_INTERRUPT);
  
  		/* watch control traffic at the token level, and force
  		 * synchronization before letting the status stage happen.
  		 * FIXME ignore tokens we'll NAK, until driver responds.
  		 * that'll mean a lot less irqs for some drivers.
  		 */
  		ep->is_in = (u.r.bRequestType & USB_DIR_IN) != 0;
  		if (ep->is_in) {
  			scratch = (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
  				| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  				| (1 << DATA_IN_TOKEN_INTERRUPT);
  			stop_out_naking (ep);
  		} else
  			scratch = (1 << DATA_PACKET_RECEIVED_INTERRUPT)
  				| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
  				| (1 << DATA_IN_TOKEN_INTERRUPT);
  		writel (scratch, &dev->epregs [0].ep_irqenb);
  
  		/* we made the hardware handle most lowlevel requests;
  		 * everything else goes uplevel to the gadget code.
  		 */
  		ep->responded = 1;
  		switch (u.r.bRequest) {
  		case USB_REQ_GET_STATUS: {
  			struct net2280_ep	*e;
  			__le32			status;
  
  			/* hw handles device and interface status */
  			if (u.r.bRequestType != (USB_DIR_IN|USB_RECIP_ENDPOINT))
  				goto delegate;
  			if ((e = get_ep_by_addr (dev, w_index)) == 0
  					|| w_length > 2)
  				goto do_stall;
  
  			if (readl (&e->regs->ep_rsp)
  					& (1 << SET_ENDPOINT_HALT))
  				status = cpu_to_le32 (1);
  			else
  				status = cpu_to_le32 (0);
  
  			/* don't bother with a request object! */
  			writel (0, &dev->epregs [0].ep_irqenb);
  			set_fifo_bytecount (ep, w_length);
  			writel ((__force u32)status, &dev->epregs [0].ep_data);
  			allow_status (ep);
  			VDEBUG (dev, "%s stat %02x\n", ep->ep.name, status);
  			goto next_endpoints;
  			}
  			break;
  		case USB_REQ_CLEAR_FEATURE: {
  			struct net2280_ep	*e;
  
  			/* hw handles device features */
  			if (u.r.bRequestType != USB_RECIP_ENDPOINT)
  				goto delegate;
  			if (w_value != USB_ENDPOINT_HALT
  					|| w_length != 0)
  				goto do_stall;
  			if ((e = get_ep_by_addr (dev, w_index)) == 0)
  				goto do_stall;
  			if (e->wedged) {
  				VDEBUG(dev, "%s wedged, halt not cleared\n",
  						ep->ep.name);
  			} else {
  				VDEBUG(dev, "%s clear halt\n", ep->ep.name);
  				clear_halt(e);
  			}
  			allow_status (ep);
  			goto next_endpoints;
  			}
  			break;
  		case USB_REQ_SET_FEATURE: {
  			struct net2280_ep	*e;
  
  			/* hw handles device features */
  			if (u.r.bRequestType != USB_RECIP_ENDPOINT)
  				goto delegate;
  			if (w_value != USB_ENDPOINT_HALT
  					|| w_length != 0)
  				goto do_stall;
  			if ((e = get_ep_by_addr (dev, w_index)) == 0)
  				goto do_stall;
  			if (e->ep.name == ep0name)
  				goto do_stall;
  			set_halt (e);
  			allow_status (ep);
  			VDEBUG (dev, "%s set halt\n", ep->ep.name);
  			goto next_endpoints;
  			}
  			break;
  		default:
  delegate:
  			VDEBUG (dev, "setup %02x.%02x v%04x i%04x l%04x "
  				"ep_cfg %08x\n",
  				u.r.bRequestType, u.r.bRequest,
  				w_value, w_index, w_length,
  				readl (&ep->regs->ep_cfg));
  			ep->responded = 0;
  			spin_unlock (&dev->lock);
  			tmp = dev->driver->setup (&dev->gadget, &u.r);
  			spin_lock (&dev->lock);
  		}
  
  		/* stall ep0 on error */
  		if (tmp < 0) {
  do_stall:
  			VDEBUG (dev, "req %02x.%02x protocol STALL; stat %d\n",
  					u.r.bRequestType, u.r.bRequest, tmp);
  			dev->protocol_stall = 1;
  		}
  
  		/* some in/out token irq should follow; maybe stall then.
  		 * driver must queue a request (even zlp) or halt ep0
  		 * before the host times out.
  		 */
  	}
  
  #undef	w_value
  #undef	w_index
  #undef	w_length
  
  next_endpoints:
  	/* endpoint data irq ? */
  	scratch = stat & 0x7f;
  	stat &= ~0x7f;
  	for (num = 0; scratch; num++) {
  		u32		t;
  
  		/* do this endpoint's FIFO and queue need tending? */
  		t = 1 << num;
  		if ((scratch & t) == 0)
  			continue;
  		scratch ^= t;
  
  		ep = &dev->ep [num];
  		handle_ep_small (ep);
  	}
  
  	if (stat)
  		DEBUG (dev, "unhandled irqstat0 %08x\n", stat);
  }
  
  #define DMA_INTERRUPTS ( \
  		  (1 << DMA_D_INTERRUPT) \
  		| (1 << DMA_C_INTERRUPT) \
  		| (1 << DMA_B_INTERRUPT) \
  		| (1 << DMA_A_INTERRUPT))
  #define	PCI_ERROR_INTERRUPTS ( \
  		  (1 << PCI_MASTER_ABORT_RECEIVED_INTERRUPT) \
  		| (1 << PCI_TARGET_ABORT_RECEIVED_INTERRUPT) \
  		| (1 << PCI_RETRY_ABORT_INTERRUPT))
  
  static void handle_stat1_irqs (struct net2280 *dev, u32 stat)
  {
  	struct net2280_ep	*ep;
  	u32			tmp, num, mask, scratch;
  
  	/* after disconnect there's nothing else to do! */
  	tmp = (1 << VBUS_INTERRUPT) | (1 << ROOT_PORT_RESET_INTERRUPT);
  	mask = (1 << HIGH_SPEED) | (1 << FULL_SPEED);
  
  	/* VBUS disconnect is indicated by VBUS_PIN and VBUS_INTERRUPT set.
  	 * Root Port Reset is indicated by ROOT_PORT_RESET_INTERRUPT set and
  	 * both HIGH_SPEED and FULL_SPEED clear (as ROOT_PORT_RESET_INTERRUPT
  	 * only indicates a change in the reset state).
  	 */
  	if (stat & tmp) {
  		writel (tmp, &dev->regs->irqstat1);
  		if ((((stat & (1 << ROOT_PORT_RESET_INTERRUPT))
  					&& ((readl (&dev->usb->usbstat) & mask)
  							== 0))
  				|| ((readl (&dev->usb->usbctl)
  					& (1 << VBUS_PIN)) == 0)
  			    ) && ( dev->gadget.speed != USB_SPEED_UNKNOWN)) {
  			DEBUG (dev, "disconnect %s\n",
  					dev->driver->driver.name);
  			stop_activity (dev, dev->driver);
  			ep0_start (dev);
  			return;
  		}
  		stat &= ~tmp;
  
  		/* vBUS can bounce ... one of many reasons to ignore the
  		 * notion of hotplug events on bus connect/disconnect!
  		 */
  		if (!stat)
  			return;
  	}
  
  	/* NOTE: chip stays in PCI D0 state for now, but it could
  	 * enter D1 to save more power
  	 */
  	tmp = (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT);
  	if (stat & tmp) {
  		writel (tmp, &dev->regs->irqstat1);
  		if (stat & (1 << SUSPEND_REQUEST_INTERRUPT)) {
  			if (dev->driver->suspend)
  				dev->driver->suspend (&dev->gadget);
  			if (!enable_suspend)
  				stat &= ~(1 << SUSPEND_REQUEST_INTERRUPT);
  		} else {
  			if (dev->driver->resume)
  				dev->driver->resume (&dev->gadget);
  			/* at high speed, note erratum 0133 */
  		}
  		stat &= ~tmp;
  	}
  
  	/* clear any other status/irqs */
  	if (stat)
  		writel (stat, &dev->regs->irqstat1);
  
  	/* some status we can just ignore */
  	if (dev->pdev->device == 0x2280)
  		stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
  			  | (1 << SUSPEND_REQUEST_INTERRUPT)
  			  | (1 << RESUME_INTERRUPT)
  			  | (1 << SOF_INTERRUPT));
  	else
  		stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
  			  | (1 << RESUME_INTERRUPT)
  			  | (1 << SOF_DOWN_INTERRUPT)
  			  | (1 << SOF_INTERRUPT));
  
  	if (!stat)
  		return;
  	// DEBUG (dev, "irqstat1 %08x\n", stat);
  
  	/* DMA status, for ep-{a,b,c,d} */
  	scratch = stat & DMA_INTERRUPTS;
  	stat &= ~DMA_INTERRUPTS;
  	scratch >>= 9;
  	for (num = 0; scratch; num++) {
  		struct net2280_dma_regs	__iomem *dma;
  
  		tmp = 1 << num;
  		if ((tmp & scratch) == 0)
  			continue;
  		scratch ^= tmp;
  
  		ep = &dev->ep [num + 1];
  		dma = ep->dma;
  
  		if (!dma)
  			continue;
  
  		/* clear ep's dma status */
  		tmp = readl (&dma->dmastat);
  		writel (tmp, &dma->dmastat);
  
  		/* chaining should stop on abort, short OUT from fifo,
  		 * or (stat0 codepath) short OUT transfer.
  		 */
  		if (!use_dma_chaining) {
  			if ((tmp & (1 << DMA_TRANSACTION_DONE_INTERRUPT))
  					== 0) {
  				DEBUG (ep->dev, "%s no xact done? %08x\n",
  					ep->ep.name, tmp);
  				continue;
  			}
  			stop_dma (ep->dma);
  		}
  
  		/* OUT transfers terminate when the data from the
  		 * host is in our memory.  Process whatever's done.
  		 * On this path, we know transfer's last packet wasn't
  		 * less than req->length. NAK_OUT_PACKETS may be set,
  		 * or the FIFO may already be holding new packets.
  		 *
  		 * IN transfers can linger in the FIFO for a very
  		 * long time ... we ignore that for now, accounting
  		 * precisely (like PIO does) needs per-packet irqs
  		 */
  		scan_dma_completions (ep);
  
  		/* disable dma on inactive queues; else maybe restart */
  		if (list_empty (&ep->queue)) {
  			if (use_dma_chaining)
  				stop_dma (ep->dma);
  		} else {
  			tmp = readl (&dma->dmactl);
  			if (!use_dma_chaining
  					|| (tmp & (1 << DMA_ENABLE)) == 0)
  				restart_dma (ep);
  			else if (ep->is_in && use_dma_chaining) {
  				struct net2280_request	*req;
  				__le32			dmacount;
  
  				/* the descriptor at the head of the chain
  				 * may still have VALID_BIT clear; that's
  				 * used to trigger changing DMA_FIFO_VALIDATE
  				 * (affects automagic zlp writes).
  				 */
  				req = list_entry (ep->queue.next,
  						struct net2280_request, queue);
  				dmacount = req->td->dmacount;
  				dmacount &= cpu_to_le32 (
  						(1 << VALID_BIT)
  						| DMA_BYTE_COUNT_MASK);
  				if (dmacount && (dmacount & valid_bit) == 0)
  					restart_dma (ep);
  			}
  		}
  		ep->irqs++;
  	}
  
  	/* NOTE:  there are other PCI errors we might usefully notice.
  	 * if they appear very often, here's where to try recovering.
  	 */
  	if (stat & PCI_ERROR_INTERRUPTS) {
  		ERROR (dev, "pci dma error; stat %08x\n", stat);
  		stat &= ~PCI_ERROR_INTERRUPTS;
  		/* these are fatal errors, but "maybe" they won't
  		 * happen again ...
  		 */
  		stop_activity (dev, dev->driver);
  		ep0_start (dev);
  		stat = 0;
  	}
  
  	if (stat)
  		DEBUG (dev, "unhandled irqstat1 %08x\n", stat);
  }
  
  static irqreturn_t net2280_irq (int irq, void *_dev)
  {
  	struct net2280		*dev = _dev;
  
  	/* shared interrupt, not ours */
  	if (!(readl(&dev->regs->irqstat0) & (1 << INTA_ASSERTED)))
  		return IRQ_NONE;
  
  	spin_lock (&dev->lock);
  
  	/* handle disconnect, dma, and more */
  	handle_stat1_irqs (dev, readl (&dev->regs->irqstat1));
  
  	/* control requests and PIO */
  	handle_stat0_irqs (dev, readl (&dev->regs->irqstat0));
  
  	spin_unlock (&dev->lock);
  
  	return IRQ_HANDLED;
  }
  
  /*-------------------------------------------------------------------------*/
  
  static void gadget_release (struct device *_dev)
  {
  	struct net2280	*dev = dev_get_drvdata (_dev);
  
  	kfree (dev);
  }
  
  /* tear down the binding between this driver and the pci device */
  
  static void net2280_remove (struct pci_dev *pdev)
  {
  	struct net2280		*dev = pci_get_drvdata (pdev);
  
  	usb_del_gadget_udc(&dev->gadget);
  
  	BUG_ON(dev->driver);
  
  	/* then clean up the resources we allocated during probe() */
  	net2280_led_shutdown (dev);
  	if (dev->requests) {
  		int		i;
  		for (i = 1; i < 5; i++) {
  			if (!dev->ep [i].dummy)
  				continue;
  			pci_pool_free (dev->requests, dev->ep [i].dummy,
  					dev->ep [i].td_dma);
  		}
  		pci_pool_destroy (dev->requests);
  	}
  	if (dev->got_irq)
  		free_irq (pdev->irq, dev);
  	if (dev->regs)
  		iounmap (dev->regs);
  	if (dev->region)
  		release_mem_region (pci_resource_start (pdev, 0),
  				pci_resource_len (pdev, 0));
  	if (dev->enabled)
  		pci_disable_device (pdev);
  	device_unregister (&dev->gadget.dev);
  	device_remove_file (&pdev->dev, &dev_attr_registers);
  	pci_set_drvdata (pdev, NULL);
  
  	INFO (dev, "unbind\n");
  }
  
  /* wrap this driver around the specified device, but
   * don't respond over USB until a gadget driver binds to us.
   */
  
  static int net2280_probe (struct pci_dev *pdev, const struct pci_device_id *id)
  {
  	struct net2280		*dev;
  	unsigned long		resource, len;
  	void			__iomem *base = NULL;
  	int			retval, i;
  
  	/* alloc, and start init */
  	dev = kzalloc (sizeof *dev, GFP_KERNEL);
  	if (dev == NULL){
  		retval = -ENOMEM;
  		goto done;
  	}
  
  	pci_set_drvdata (pdev, dev);
  	spin_lock_init (&dev->lock);
  	dev->pdev = pdev;
  	dev->gadget.ops = &net2280_ops;
  	dev->gadget.max_speed = USB_SPEED_HIGH;
  
  	/* the "gadget" abstracts/virtualizes the controller */
  	dev_set_name(&dev->gadget.dev, "gadget");
  	dev->gadget.dev.parent = &pdev->dev;
  	dev->gadget.dev.dma_mask = pdev->dev.dma_mask;
  	dev->gadget.dev.release = gadget_release;
  	dev->gadget.name = driver_name;
  
  	/* now all the pci goodies ... */
  	if (pci_enable_device (pdev) < 0) {
  	        retval = -ENODEV;
  		goto done;
  	}
  	dev->enabled = 1;
  
  	/* BAR 0 holds all the registers
  	 * BAR 1 is 8051 memory; unused here (note erratum 0103)
  	 * BAR 2 is fifo memory; unused here
  	 */
  	resource = pci_resource_start (pdev, 0);
  	len = pci_resource_len (pdev, 0);
  	if (!request_mem_region (resource, len, driver_name)) {
  		DEBUG (dev, "controller already in use\n");
  		retval = -EBUSY;
  		goto done;
  	}
  	dev->region = 1;
  
  	/* FIXME provide firmware download interface to put
  	 * 8051 code into the chip, e.g. to turn on PCI PM.
  	 */
  
  	base = ioremap_nocache (resource, len);
  	if (base == NULL) {
  		DEBUG (dev, "can't map memory\n");
  		retval = -EFAULT;
  		goto done;
  	}
  	dev->regs = (struct net2280_regs __iomem *) base;
  	dev->usb = (struct net2280_usb_regs __iomem *) (base + 0x0080);
  	dev->pci = (struct net2280_pci_regs __iomem *) (base + 0x0100);
  	dev->dma = (struct net2280_dma_regs __iomem *) (base + 0x0180);
  	dev->dep = (struct net2280_dep_regs __iomem *) (base + 0x0200);
  	dev->epregs = (struct net2280_ep_regs __iomem *) (base + 0x0300);
  
  	/* put into initial config, link up all endpoints */
  	writel (0, &dev->usb->usbctl);
  	usb_reset (dev);
  	usb_reinit (dev);
  
  	/* irq setup after old hardware is cleaned up */
  	if (!pdev->irq) {
  		ERROR (dev, "No IRQ.  Check PCI setup!\n");
  		retval = -ENODEV;
  		goto done;
  	}
  
  	if (request_irq (pdev->irq, net2280_irq, IRQF_SHARED, driver_name, dev)
  			!= 0) {
  		ERROR (dev, "request interrupt %d failed\n", pdev->irq);
  		retval = -EBUSY;
  		goto done;
  	}
  	dev->got_irq = 1;
  
  	/* DMA setup */
  	/* NOTE:  we know only the 32 LSBs of dma addresses may be nonzero */
  	dev->requests = pci_pool_create ("requests", pdev,
  		sizeof (struct net2280_dma),
  		0 /* no alignment requirements */,
  		0 /* or page-crossing issues */);
  	if (!dev->requests) {
  		DEBUG (dev, "can't get request pool\n");
  		retval = -ENOMEM;
  		goto done;
  	}
  	for (i = 1; i < 5; i++) {
  		struct net2280_dma	*td;
  
  		td = pci_pool_alloc (dev->requests, GFP_KERNEL,
  				&dev->ep [i].td_dma);
  		if (!td) {
  			DEBUG (dev, "can't get dummy %d\n", i);
  			retval = -ENOMEM;
  			goto done;
  		}
  		td->dmacount = 0;	/* not VALID */
  		td->dmaaddr = cpu_to_le32 (DMA_ADDR_INVALID);
  		td->dmadesc = td->dmaaddr;
  		dev->ep [i].dummy = td;
  	}
  
  	/* enable lower-overhead pci memory bursts during DMA */
  	writel ( (1 << DMA_MEMORY_WRITE_AND_INVALIDATE_ENABLE)
  			// 256 write retries may not be enough...
  			// | (1 << PCI_RETRY_ABORT_ENABLE)
  			| (1 << DMA_READ_MULTIPLE_ENABLE)
  			| (1 << DMA_READ_LINE_ENABLE)
  			, &dev->pci->pcimstctl);
  	/* erratum 0115 shouldn't appear: Linux inits PCI_LATENCY_TIMER */
  	pci_set_master (pdev);
  	pci_try_set_mwi (pdev);
  
  	/* ... also flushes any posted pci writes */
  	dev->chiprev = get_idx_reg (dev->regs, REG_CHIPREV) & 0xffff;
  
  	/* done */
  	INFO (dev, "%s\n", driver_desc);
  	INFO (dev, "irq %d, pci mem %p, chip rev %04x\n",
  			pdev->irq, base, dev->chiprev);
  	INFO (dev, "version: " DRIVER_VERSION "; dma %s\n",
  			use_dma
  				? (use_dma_chaining ? "chaining" : "enabled")
  				: "disabled");
  	retval = device_register (&dev->gadget.dev);
  	if (retval) goto done;
  	retval = device_create_file (&pdev->dev, &dev_attr_registers);
  	if (retval) goto done;
  
  	retval = usb_add_gadget_udc(&pdev->dev, &dev->gadget);
  	if (retval)
  		goto done;
  	return 0;
  
  done:
  	if (dev)
  		net2280_remove (pdev);
  	return retval;
  }
  
  /* make sure the board is quiescent; otherwise it will continue
   * generating IRQs across the upcoming reboot.
   */
  
  static void net2280_shutdown (struct pci_dev *pdev)
  {
  	struct net2280		*dev = pci_get_drvdata (pdev);
  
  	/* disable IRQs */
  	writel (0, &dev->regs->pciirqenb0);
  	writel (0, &dev->regs->pciirqenb1);
  
  	/* disable the pullup so the host will think we're gone */
  	writel (0, &dev->usb->usbctl);
  }
  
  
  /*-------------------------------------------------------------------------*/
  
  static const struct pci_device_id pci_ids [] = { {
  	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
  	.class_mask =	~0,
  	.vendor =	0x17cc,
  	.device =	0x2280,
  	.subvendor =	PCI_ANY_ID,
  	.subdevice =	PCI_ANY_ID,
  }, {
  	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
  	.class_mask =	~0,
  	.vendor =	0x17cc,
  	.device =	0x2282,
  	.subvendor =	PCI_ANY_ID,
  	.subdevice =	PCI_ANY_ID,
  
  }, { /* end: all zeroes */ }
  };
  MODULE_DEVICE_TABLE (pci, pci_ids);
  
  /* pci driver glue; this is a "new style" PCI driver module */
  static struct pci_driver net2280_pci_driver = {
  	.name =		(char *) driver_name,
  	.id_table =	pci_ids,
  
  	.probe =	net2280_probe,
  	.remove =	net2280_remove,
  	.shutdown =	net2280_shutdown,
  
  	/* FIXME add power management support */
  };
  
  MODULE_DESCRIPTION (DRIVER_DESC);
  MODULE_AUTHOR ("David Brownell");
  MODULE_LICENSE ("GPL");
  
  static int __init init (void)
  {
  	if (!use_dma)
  		use_dma_chaining = 0;
  	return pci_register_driver (&net2280_pci_driver);
  }
  module_init (init);
  
  static void __exit cleanup (void)
  {
  	pci_unregister_driver (&net2280_pci_driver);
  }
  module_exit (cleanup);
  